Note: Descriptions are shown in the official language in which they were submitted.
21 8825~
~ WO 95/34633 r~
lM~KUV~:iV ~'K~ _ ~ CAST D3T~R~NT
Field of the I~vention
The invention relates to a novel solid cast
5 warewashing detergent useful to prepare low foaming
aqueous detergents. The detergents are formulated with
an optimized content of a selected biodegradable
nonionic material to enhance soil removal, with little
foaming, in institutional di9hwashing machines and
10 industrial washing machines. The invention also relates
to a method for producing the low foaming detergent
containing article. The invention also relates to a
method for using the detergent cnnt~;n;n~ article. The
materials of the invention can remove food soils,
15 preferably proteinaceous and dairy soils, efficiently
with little or no associated filming or residue buildup.
Back~Jround of the Tnve~tio~
Solid cast high performance detergent containing
20 articles are known for use in institutional dish or
warewashing machines and industrial washing machines
using an aqueous cleaning medium at both high (145F and
up) and low (120-145F) water temperature. The advent
of such high performance products was stimulated in part
25 by increased aesthetic and sanitary requirements and a
demand for shorter wash times. Such high performance
products are generally complex detergent compositions
that posse8s high ~ 1 k~ 1 i n; ty as a soil
removing/degrading component (e . g , substantial
30 concentrations of sodium hydroxide). In addition to a
source of ~lkAl;n;ty, chemicals used in high performance
products, particularly for hard surface cleaning (e.g.,
warewashing) include additional sources of i~lk~l;n;ty,
organic and inorganic sequestrants such as a poly
35 acrylic acid material, NTA, polyphosphates, chlorine-
~-nnt;~;n;ng compounds, nonionic defoamer8, thickeners,
etc .
A source of available chlorine i8 often included to
control food stains, such as tea and coffee stains. The
21 8~3256
Wo 95l34633 P~~ 77
defoamer is often~.included to control foam crea~ted by an
interaction between proteinaceous ~oil, saponified ~ats
and water in the cleaning medium. See Mizuno et al., .L
U . S . Patent No . 3 ,16~, 513; Sabatelli et al ., U . S . Patent
No. 3,535,285; Sabatelli et al., U.S. Patent No. ~,
3,579,455; Mizuno et al., U.S Patent No. 3,700,599; and
~,r~ n.l et al-,` ~.S. Patent No. 3,899,436.
~ommonly, nonionic defoaming compositions used in
available compos~ tions comprise a pluronic or reverse
pluronic nonionic. Pluronic nonionics comprise a
nonoionic E0 bloc~$-P0 block-E0 block stricture. Rever~e
pluronics have a P0 block-E0 block-E0 block structure.
The~e materials are common in detergent chemistry and
particularly in cast solid detergent technology. These
materials are typically used in an amount of about o .
to about 1.5 wt-~ to obtain suitable defoaming of
a~ueous wash compositions made using effective amounts
of the detergent composition.
The high :~lki~l;n~ compositions of the prior art,
while generally effective, can experience a reduced
e~fectiveness depRnding on water conditions, 60il type,
water temperatureP-, etc . Morganson et al ., U. S . Pat .
No. 5, 080, 819 teach the use of a proportion of a broad
range of types of nonionic material to enhance cleaning.
We have f ound that a particular soil arising f rom
highly prot~;n;:c~ foods such as dairy products form a
f ilm highly resistant to removal using conventional
warewashing dete~gents that can include typical nonionio
defoamer compositions. Typically, coffee cups and
drinking glasses are particularly subject to formation
of proteinaceous dairy derived soil residues. Glasses
used to serve milk, chocolate milk, shakes, malts,
f loats, etc . which come in contact with substantial
proportion~ of dairy protein, obtain a F~tu~born film
resistant to cleaning using ;~lk~l ;n~ material . Further,
coffee Cl;lpS used in ~erving cof~ee combined with
21 88256
Wo 95~34633 P~ U.,~.~1f'7'~
creamers (whole cream, half-n-half, non-dairy creamer
substitutes) can also form a dairy based stubborn film
resistant to removal using alkaline cleaner materials.
We have found that because of the reuse frequency of
5 glasses and cups, the proteinaceous dairy derived f ilms
rapidly f orm and become a relatively permanent f ilm
present on the surface of the silicate or ceramic
~urf aces . We have f ound that in large part, the
nonionic defoamer materials either participate in the
formation of the films or have little or no efficacy in
their removal during warewaehing. These films can also
form on other ware if washed in batches cnnti~;nlng dairy
soil contaminated cups or glasses.
Due to envi~ l concerns and requirements, a
strong need for biodegradable or envirf)nm~nt~l ly
friendly materials in cast solid detergents are needed.
Many nonionic materials that can defoam or effectively
increase the cleaning power of alkaline detergents have
been found but are slow to degrade in envi" -nti~l
conditions. Many of the Morganson et al. surfactants
are not considered to be biodegradable under current
standards. We have also found many nonionic materials
that are effective cleaners, and are biodegradable, but
are unfortunately high foaming. Accordingly, while the
materials satisfy requirements for cleaning and
biodegradability, their use is limited by the degree to
which they foam during cleaning operations in
institutional or industrial cleaning apparatus. The
generation of high levels of foam can interfere with
3 0 contact between the eurf ace of the ware and a cleaning
spray, can interfere with pumping the aqueous cleaning
medium through the machines, and can cause an overflow
of foam from the m-~-h;no,~ creating a hazardous situation
in the cleaning location. In our work to effectively
defoam the ~lk~lln~ materials having cleaning nonionics,
we have found a class of nonionic soil removing
compositions that efectively defoam but are also
2 1 882~
Wo 9sl34633 PCrlUS95/02283
biodegradable. The biodegradable rl.o~n;ng nonionic
material and the biodegradable foam control nonionic
material cooperat~ in the detergent to produce e~cellent ~'
cleaning and in particular, ~ nt soil and protein
5removal leaving little or no film or residue while ~
generating little or no foam during cleaning operations.
ry Of the Inventio~
10We have also found that ~he cleaning problems
described above can be minimized by forming a solid cast
detergent ~nt~;n;nr~ a defoaming composition and a
biodegradable cap~ed alcohol ethoxylate nonionic soil
removing composition in a disposable mold. The
15detergent is used and dispensed by a water spray
directly f rom the mold/cast detergent combination . The
cast detergent composition comprises an alkali metal
hydroxide, at least about 0.5 wt-l; (0.1 to 15 wt-9~ can
be used, preferably 0.2 to 5 wt-~, most preferably 0.25
20to 1 wt-9~) of a -capped alcohol ethoxylate soil removing
surfactant, a hardness se~uestering agent and water of
hydration. The combination of the cast detergent and
the disposable mold in which it was f ormed provides an
article of commexce capable of dispensing dissolved
25solids from substantially only one side of the surface
which was the free or unsupported surface in the mold.
Alternatively, the solid cast detergent composition can
be removed from the mold in which it is formed prior to
use .
The nonionic soil removing detergent composition
has the f ormulae:
RO- (EO) x-A
wherein A is any capping moiety, preferably A is a non-
aromatic capping moiety and x is 6 to 50, preierably 6
to 40, and most preferably 6 to 20. The preferred end
group or capping moiety is a butylene oxide cap (BO) y
wherein y is 1-5, preferably 1-3. The nonionic soil
t 215~256
removing detergent com~ositions a~e ethylcne ox~de based
block materialo having an end or cappins sroup. The end
cap moietiea tcap A) is derived ~rom compounds that form
otherwise stable capping moietiea. ~h~ e~d caps c~n be
formed from C~ or higher alkylene oxide including 1, 2-
butylene oxide, 2,3-butylene oxide, 1,2-pentene oxide,
- ~tc. ~he end ~apg can be forr~ed ~rom alkyl or aliphatic
end groUp forming compounds. Alkyl groups can include
methyl, ethyl, propyl, isopro~yl, n-butyl isobutyl,
- 10 cyclohexyl; halogens incluc'ing chloro, bromo, iodo,
etc.; halo alkan~ suc~ as chloro methane, chloro butane,
dichloropentane; alcohol~ such as metharlol, ethanol, 2-
propano~L, cy~ h~ nnl ~ polyhydric alcohol such aB 1, Z -
ethane diol, 1,4-benzene diol and the liks; mercaptans
~uch as methane thiol, 1,2-meth~ne dithiol and the like;
moieties formad ~rom reactive compo~ds such as
epichlorohydrin, t~tram6~thylenc oxide, ald~hydes,
ketones, carboxyl~te containi~g ~o~ro~n~^ such as the
al~ali metal ~alts o~ carboxylic acida and t~.e estera o~
carboxylic acids ~nd their anhydr~ides. The above
liating i8 exerplary and not in~ i to be limiting
since the Ghe~ y Etab~Le end s~roups that atabilize
the polymer and provide its r1~.An;r~j activity are known
in the manu racturins of block nonionic rt,~terials .
~he deterg~nt compoDition ~ ~ normally formed by
m~xing and hèating th~ n~B in an a~ueous
solution, ~h~-k~-n~ ~5 the solu~ion, E)ourins the Eolu~ion
into the mol~ and prefer~bly ~lEo cooling it, and
allowi~g the mixture to solidi~y. The Eolidification
can involve one or more physico-chemical r^-h ~nl ~
i~cluding "~re~zing", precipitatiorL from solution,
hydration, etc. Preformed plug~ or CoreE of a chlorine
source and/or a defoamer can be inerted in the mixture
after it ha~ been added to a mold an~g be~o~e it has
801 i ~ ; f ~ ed .
~he c~st detergent composition ia preCer^bly leAft
~tEN~ED SHE~T
.. . . . .. . .. . . . ... . .. . . . .
2 ~ 88256
WO95l34633 ~ ITJ., _'n~7Q';
in the disposable mold in which it was cast.
Alternatively, the cast detergent can be demolded and
inserted in an inexpensive cnnt:,;nf~r or receptacle or
directly into a dispenser which has subst;3nt;~lly the
same configuratioA as the mold, since in either case the ~
cast detergent is surrounded on all but one surface, as
described previously. The thus-~uLL~ullded cast
detergent is used by placing its exposed surface in a
drainable positio~ (preferably fixed~ within a detergent
dispensing apparatus. A fixed drainable position is one
in which the afn tinnT~T~ unsurrounded, exposed
surace is fixed with respect to the horizontal and a
potential impinging spray of liquid such that the
unsurrounded, exposed surface permits gravity flow
therefrom, either because of an inclination from the
horizontal by a degrees (e.g., by 10-90) or by
inclination beyond 90TJ, i.e., partial or total inversion
up to and including a totally inverted or downward-
facing position. A spray of liquid impinging on the
drainable (;ncl ;nf~Tl or inverted) surface, suitably
controlled in duration, provides a draining action or
gravity flow of liT~uid detergent which drai~s downward
of f of the drainable surf ace to the washing machine into
which the detergent is to be dispensed. Control over
the duratio~l of impingement (hence the duration of
downward flow) has the e~fect o~ controlling the
concentration o detergent in the washing machine. The
dispensing apparatus is not a water-in-reservoir type,
since it dispenses the flow of liquid detergent about as
fast as this flow is formed by the spraying action.
We have ~ound that food soils, preferably
proteinaceous soils, most preferably dairy based soils,
can be removed with surprising effectiveness using
highly alkal ;nF~ cast solid detergent cnnt~;n;nT~ a soil
removing nonionic~ material comprising a capped
polyethylene oxiTl~ polymer . We have f ound that many
nonionic materials currently used in warewashing systems
2 1 ~8256
Wo 95~34633 . ~~ ?~
either fail to remove proteinaceous films or soils from
hard surfaces or cooperate with the goil sources to form
tenacious films. However, regardless of the soil
nature, the capped polyethylene oxide nonionic soil
~- 5 removing materials of the invention cooperate with the
other components of a cast solid detergent to
8ubstantially increase the cleaning capacity of the cast
solid detergent8 resulting in cleaned ware with no
tendency to promote filming or other hard to remove soil
type. The8e nonionic materials are preferred for use in
the cast solid detergent compositions because of their
performance and biodegradability. These materials when
introduced into the environment af ter their use in
cleaning, rapidly degrade to nontoxic residues that can
be metabolized by organisms in the environment.
Certain of the soil removing surfactants 8et forth
above can generate foam. Others can be used without
substantial foam generation, however the cast 801id
detergents of the invention using the improved nonionic
surfactant materials can be made with a defoaming
nonionic to further improve 80il removing performance.
The solid cast warewashing composition of the
present invention should comprise about 0.1 to 15 wt-~
of a nonionic surfactant for reasons of fatty soil
emulsification, preferably about 0.2 to 10 wt-~ for
reasons of optimum fatty soil emulsification, and mo3t
preferably about 0.3 to 9 wt-~ for reasons of most
optimum soil emulsification.
one necessary component for producing the solid
3 0 cast detergent compo~ition of the pre~ent invention i~
an alkali metal hydroxide. Suitable alkali metal
hydroxide~ include, but are not limited to, the
following: sodium hydroxide and potassium hydroxide.
Preferably the solid cast detergent composition
comprises sodium hydroxide for economic reasons. These
materials are available in aqueous f~ n~rate or in
bead form. The alkali metal hydroxide will normally
_ _ _ _ _ _ _ _ _ _ . . . .
21 88256
Wo 95l34633 r~
comprise about 10 to 60 wt-~ o~f the detergent
compo6ition for reasons of chemical soil removal,
preferably 20 to 5~ wt-~6 for reasons of more cost
effective soil removal, and most preferably about 35 to
50 wt-% for reasorls of most cost effective 80il removal. .,
If the alkali metal hydroxide collcentration is too low,
chemical soil removal performance will deteriorate. If
the alkali metal ~ydroxide ~.nr-~ntration is too high, an
increase in use c,ost will result~.
A second necessary component of the solid cast
composition of this invention is water. Water is used
in combination with alkali metal hydroxide to form a
meltable carrier medium cont~;n;n~ the detergent
components; the medium being cast into a mold and
sol;~;f;l~l by a solidification mechanism described
previously. Water may be added as a separate ingredient
or in combination with one of the other components, for
example as an aqueous solution of 50% sodium hydroxide
The water of hydration will normally comprise about
5 to 30 wt-~ of the detergent composition, preferably
about lo to 20 wt-9~ for reasons of keeping the mixture
f luid and processable at a temperature ranging f rom
about 155-180F and mos~ preferably about 12 t~ 15 wt-%
for reasons o~ keeping the mixture fluid and rr~o~.qq~hlG
at a temperature ranging from about 1~5-18ooF.
A third n~e,q,q~ry component of the solid cast
detergent composition is a sequestrant. The solid cast
wa-~. qh;ng composition of the present invention should
comprise about 16 to 50 wt-~ o~ sequestrant=,,, preferably
about 15 to 31 wt-% for reasons of cost performance
legal restrictions, and most preferably about 20 to 30
wt-9~ for reasons Qf optimum cost performance.
The service ~ater com,monly employed in cleaning
baths contain substantial proportions of hardness ions
most commonly calcium and magnesium ions, which can
react with detergent components to decrease cleaning
e~ectiveness and/or leave unsightly deposits upon the
-
2 1 88256
WO 95l34633 P~ A7~Q~
substrate being cleaned. Sequestrants act to prevent or
delay crystal growth of calcium or magnesium compounds
and thereby ~1; m; nAte their reaction with other
components and/or their precipitation. Suitable
,. 5 sequestrants for use in the 901id cast detergent
composition of the present invention include organic and
inorganic sequestrants. Organic 8equestrants include a
broad class of materials that can complex hardness ions
such as calcium, magnesium, iron, manganese and others.
Organic sequestrants include EDTA (ethylene diamine
tetraacetic acid and its salts), NTA (nitrilotriacetic
acid and its salts), polyelectrolytes such as
polyacrylic acid and its copolymers, polymaleic acid and
its copolymers and others. Inorganic hardness
sequestering agents include condensed phosphates,
particularly phosphates of the formula M- (PO3M) nOM
wherein M is an alkali metal and n is a number ranging
from 1 to about 60, typically les8 than 3 for non-cyclic
phosphates, typical examples of such phosphates being
sodium or potassium orthophogphate and ~lkAl ;n~
condensed phosphates (i.e., polyphosphates) such as
sodium or potassium pyrophosphate, sodium
tripolyphosphate, sodium hexametaphosphate, etc.
Preferably, the sequestrant comprises sodium
tripolyphosphate for reasons of sequestration,
peptl zing, and soil suspension.
Preferably, the sequestrant is utilized in its
anhydrous form for reasons of cost. EIowever, a
sequestrant in its hydrated form could be utilized if
the water content of the other raw materials is adjusted
downward to ~nmrPn=Ate for the water of hydration
contained in the sequestrant.
In addition to those components previously
described, other convont;nnAl detergent components and
fillers can be included. For example, it is possible to
include a def oamer .
Defoamers, in addition to the above-mentioned
-
~ 1 88?56
Wo 95l34633
nonionic surfactant:s, can also be included in the solid
cast detergent composition. np~o:~mf~rs will normally
comprise minor amounts of the solid cast detergent
composition, i.e. about 0.1 to 5 wt-96, for reasons o~
cost performance, preferably about 0.1 to 2 0 wt-% for ~!
reasons of optimum cost performance, and most preferably
about 0.2 to 0.5 wt-3~ for reasons of most optimum cost
performance. Typically, a "defoamer" is a chemical
compound with a hydrophobe\hydrophile balance suitable
10 to reducing the stability of protein foam. The
hydrophobicity can be provided by an oleophilic portion
of the molecule ~e . g ., an aromatic alkyl or arylalkyl
group. The hydrophilicity can be provided with
oxyethylene units in chains or blocks and/or ester
15 groups (e.g., organophosphate esters), salt-type groups,
or salt-forming groups. Typically, defoamers are
nonionic organic block polymers having hydrophobic
groups or blocks Qr chains and hydrophilic ester groups,
blocks, units, or chains. For a disclosure of nonionic
29 d~fQ~m;ns sur~a~-~=Antsl see IJ.S . Patent ~o . 3, 048, 548,
issued August 7 , 1962 (Martin et al . ), U. S . Patent ~to .
3,334,147, issued August 1, 1567 (Brunelle et al.), and
U.S. Patent No. 3,442,242, issued May 13, 1969 (Rue et
al . ) . Phosphate esters are also suitable, e . g ., esters
2~ of the formula Ro- (Po3M) -~,R, wherein n i8 a3 defined
previously and R is an organic group or M (as def ined
previously), at least one R being an organic group such
as an oxyalkylene chain.
The solid c~.~st detergent composition can optionally
30 further comprise about 1 to 20 wt-~ of hydratable,
cry~talline alkali metal silicate ior ~asons Df soil
suspension, and providing ~lk~l ;n;ty and corrosion
protection, preferably about lo to 20 wt-~6 for reasons
of providing optimum soil suspension, providing
35 additional ~lk~1;n;ty and corrosion protection and most
preferably about 12 to 18 wt-% for reasons of providing
most optimum soil suspension, providing additioual
21 8~256
Wo 95l34633 PCT/US9~/02283
11
l k~ l; n; ty and corrosion protection .
Alkali metal æilicates are the reaction product of
an alkali metal oxide (M20) and silicone dioxide (sioz)
and have the general rh~m;r~l formula (M20)X (SiOl)y
,. 5 wherein x and y indicate the molar ratio of alkali metal
oxide to silicon dioxide.
Methods of manufacturing alkali metal 6ilicates
having various x:y mole ratios are well known as
demonstrated by the general disclosure in Kirk Othomer
Encyclopedia of Chemical Technology, 2d Ed., Vol. 18,
pp. 139-141. The desired properties and benefits of the
solid cast detergent composition described herein can be
obtained by using an alkali metal silicate having an x:y
ratio of about 1:1-3:1, preferably 1:1-2:1. At t~ese
ratios, the alkali metal silicate has sufficient
;~lk~lin~ character to clean effectively and sufficient
silicon dioxide to protect aluminum, china, glassware,
etc. from the etchant effect of basic components in the
composition. These silicates also have excellent
solidification properties.
For reasons of high cleaning performance, delicate
ware protection and low cost, the most preferred alkali
metal silicate i8 sodium metasilicate having an Na20: SiO2
ratio of about 1:1-2.1. Preferably anhydrous alkali
metal silicate is utilized to minimize water content in
the f inal product and optimize u3e cost by concentrating
the product.
The solid cast detergent composition can optionally
further comprise a r~rhnn~te such as sodium carbonate
and potassium carbonate. Carbonates can comprise about
1 to 30 wt-% of the detergent composition, preferably
about 1.5 to 25 wt-96 for reasons of cost opt;m;7~t;on~
and most preferably about 1.5 to 20 wt-9~ for reasons of
optimum cost optimization.
Carbonates serve the following function in the
solid cast detergent composition of the present
invention, they hydrate water and solidify the product
_ _ . _ _ .. _ . .. , ... , , . . _ _ _ _ _
2 ~ ~236
Wo 95/34633 r~ r7-
~
13
exceed 100 cm2, e.g., 125 cm2 to 1000 cm~ or more.
Unlike compressed detergent tablets, it has been found
that cast detergent blocks can be made very large -- =
almost any desired size.
, 5 The mold or ,-,,nt~;nor can be made of any alkali-
resistant material which can withstand moderately
elevated temperatures, e.g., 150F, and which can be
formed into and hold the desired shape. Since the mold
is generally intended to be "disposable" (i.e., not
intended for reuse as a mold), inexpensive materials are
preferred such as thermoplastics, resin-impregnated
heavy paper or cardboard, and the like. Inexpensive but
fragile material such as glass or ceramics are less
pref erred due to handling or shipping problems,
relatively flexible materials being preferred. Molds
made of plastic (e.g., inexpensive thermoplastics) have
been found to be particularly useful.
The solid cast detergent cont;l;n;ng article can be
used in con]unction with a detergent dispensing
apparatus which can be part of a conventional
institutional or industrial washing machine. The
article, including base detergent and container is
placed in a totally downward-facing or totally inverted
position over a spray means which is connected to a
water source, whereby the exposed surface of detergent
becomes a drainable surface. When the water source is
turned on, the spray means causes water to impinge on
the exposed surf ace of detergent . The detergent
dissolves, creating a gravity f low of liquid aqueous
detergent which flows downwardly through a pipe to a
wash tank or washing zone of the washing machine. The
detergent composition can be formulated to dissolve at
substi~ntl~lly the same rate and thus supply the tank
with a consistent ratio of ingredients.
By controlling the spray time, the amount of
detergent, and thereby the concentration of detergent,
the wash can be controlled. In other words, the liquid
2 ~ ~2~
Wo 9~/34633 F~
14
a~ueous detergent formed as a result of the impingement
of the spray on the exposed surface of detergent flows
by gravity into a pipe generally simultaneously with its
iormation within the dispensing apparatus. Standing
water or aqueous liquid is not permitted to accumulate .,
within the dispensing apparatus.
Method of Manufact~L~inq Cast Deterqent
The solid cast detergent composition of the present
invention can be formed by a number of methods
including, but not limited to, batch processing and
Gemicontinuous processing.
While the following processes are described with
reference to specific components, it should be
understood that other components and !iimilar processes
can be used to form a detergent solution which can be
cast into a mold and which will solidify upon hydration
of its hydratable component to form a solid cast
detergent composition. The solid cast detergent
composition of this invention can be manufactured by
combining the components in a suitable mixer having
sufficient resiqta~nce to chemical attack from the
ingredients and sufficient mixing capacity. While the
ingredients can be mixed generally in any order without
substantially reduced properties, the preferred mode of
preparing the composition is f irs~ charging to a large
industrial scale mixer an aqueous solution of an alkali
metal hydroxide. Mixing and heating the aqueous
solution of alkali metal hydroxide re8ult in a mixable
3 0 f luid matrix . Into the aqueous solution in the
industrial mixer can then be placed the balance of the
components . If the sequestrant llt i 1 i 7~fl contains
phosphate, it is preferably added near the end of the
process in order to minimize phosphate reversion.
The industrial mixer is operated at a suf ficient
speed and hUL ~t:,uu .~cr and temperature range to insure
adequate mixing of the components. Once the components
21 88256
Wo 95l34633 P~
are fully mixed and uniform, the composition is drawn
off into molds or capsules for solidification.
During processing the components are preferably
mixed and drawn off into the capsule or mold while
,, 5 maintaining the temperature of the composition at about
144-155F for reasons of keeping the product molten and
thus processable, preferably about 144 to 150F for
optimum processability. The process must be run at a
minimum of about 144F throughout in order to m~;nt~1n a
molten product.
A particularly useful detergent composition of this
invention is formed by heating about 60 to 70 parts by
weight of a 40-75 wt-9~ aqueous solution of an alkali
metal hydroxide , e . g ., sodium hydroxide , to a
temperature of about 144-155F, preferably about 144-
180F for reasons of optimum processing. The alkali
metal hydroxide solution is then mixed at a suf f icient
rate for effective heat distribution and in order to
keep the solution mixed and flowing. While other alkali
metal hydroxides may be used, sodium hydroxide has been
found to be particularly useful and the following method
of manufacturing will be described with respect to it.
Aqueous solutions of 50 wt-~6 sodium hydroxide are
readily commercially available. Solutions ~rnt:~;n1n~
higher weight percents of sodium hydroxide are also
available (e.g., 73~) or can e produced by adding a
desired amount of anhydrous sodium hydroxide to a 50 wt-
96 solution of sodium hydroxide. An aqueous solution of
sodium hydroxide can also be prepared by mixing water
3 0 and anhydrous sodium hydroxide in the desired ratio .
About 30 to 40 wt-96 of anhydrous sodium hydroxide beads,
preferably about 35 to 40 wt-96 for reasons of
establishing the proper matrix, and most preferably
about 34 to 36 wt-~ are then added to the mix tank. The
addition of the anhydrous sodium hydroxide beads brings
up the concentration of sodium hydroxide in the mixture
to its f inal level . With the addition of the anhydrous
2 1 88256
Wo 95l34633 PC rlUSssl02283
16
sodium hydroxide beads there is no longer any free water
in solution resulting in a molten matrix.
Next, the nonionic soil removing surfactant is
added to the mix ~ank. The soil removing surfactant
5 alone can be added with a defoamer mixed Dr
sequentially. Mixing shDuld occur for a sufficient
amount of time in order to render the mix tank contents
homogeneous. About 20 to 35 wt-96 of a sequestrant such
as sodium tripolyphosphate can then be added to the mix
10 tank. Alternatively, a æodium tripolyphosphate
surfactant premix can be added at this time.
About 20 to 5 wt-~6 af a sodium tripolyphosphate
surf actant premix can then be added to t~e mix tank .
The "sodium tripolyphosphate surfactant premix~ i6 as
15 defined in ~xample 1. Phosphate ~ nt;:;n;n~ compositions
are preferably added late in the process to minimize
phosphate reversion.
About o to 0.135 Wt-9G of a dye can then be added to
the mix tank contents. The dye i9 typically added near
20 the end of the process to protect the dye, but not 50
late that there is sufficient time fo~ the dye to be
adequately blended with the mix tank contents.
Af ter the sequestrant such as a pDlyphoaphate
and/or optional ~illers or component~3 (the polyphosphate
25 is a preferred ingredient, are addedr the mixtu~re can be
cooled. ~r"n~; nl~nuS mixing can be u~ed during any
dissolvin~, coolin~ and thickening steps. The cooled
and thickened mixture is poured into a receptacle-shaped
mold to a level at least part way up the side molding
30 surfaces. As the mixture c~n~;nlle~ to cool, it will
solidify to form a cast composition. Solidif ication is
believed to be eubstantially due to cooling. (This
invention is not bound by a theory, however~. After it
has solidif ied, the cast detergent is surrounded by and
35 in contact with the mold on all sides except for its
upper surf ace which remains exposed .
Ilhe present invention will be further understood by
2~ 882~6
W0 95/34633 r~ x~
17
reference to the following specific Examples which are
illustrative of the composition, form and method o~
producing the solid cast detergent c~nt~;ning article of
this invention. It is to be understood that many
,, 5 variations of composition, form and method of producing
the cast detergent would be apparent to those skilled in
the art . The f ollowing Examples, wherein parts and
percentages are by weight unless otherwise indicated,
are only illustrative.
WO 95/34633 : 2 ~ 8 ~ 2 ~ ~ PCI/US95/022~3
~x~erimental
The invention is a performance impluv t ~ with the
sur~actants used in automatic difihwash detergents, The
;, Luv,:":ent is an lmprûved ability to remove dried
protein soil residues from tableware. Results are ~,
measured as better spot grades on glasses . The benef it
is tableware with an improved appearance,
The specific surfactant used to improve performance
is a nonionic with the following structure:
Cl3,ls alkyl-û- (EO) ~-10 (BO) 1-2
EO~ = Ethylene Oxide
BO = Butylene Oxide ,
The reason that new sur~actants were investigated
is that the block polymer nonionics commonly used do not
rernove dried protein soil ~rom tableware We think that
protein residue frûm coffee creamer adheres to the
inside of coffee Cl'pS and becomes stai~ed This is very
unsightly and causes customer complaints.
The experimental meth~d used to demonstrate the
performance benefit is a laboratory spot and film test.
The procedure and equipment is as ~ollows:
This is a 20 cycle test using a Hobart C-44
high/temperature conveyor rack machine During the
test, city water (5 grains) wa6 used. Temperatures were
165F wash and 185F rinse. To the wash water ~was
mA;nt~;ne~l 500 ppm food soil con5i5ting of a 50/50
mixture of pureed Dinty Moore Beef Stew and Hot Point
Soil. Hot Point Soil is made from a mixture ûf 4 parts
Blue Bonnet marga~ine and one part Carnation powdered
milk. The glasses that were run thrûugh the 20 cycle
test were dipped completely inside and out into Land-O-
Lakes whole milk, and dried for 5 minutes in a 100F
oven at ambient humidity, The wash water was m-~nt;~i
with 1000 ppm of test detergent throughout the
evaluation.
At the end of the twenty cycles, the test glasses
were rated,for spots. The rating scale is 1-5 with 1
21 ~8256
WO 95/34633 ~ ~. "
19
being no spots and ~ being heavily spotted. Test
glasses were compared to laboratory standards and rated
in a laboratory light box.
,r
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WO 95134633 ~ A77~ --
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WO 95/34633 2 i 8 8 2 5 6 PCT/USgS/02283
Spot grades were as folIows:
Formulation
5.0
2 3.0
., 5 3 5.0
4 . 3.0
Results ~how that ~he BASF ~F 221 is responsible for
the improved spot grades V8. the detergent made with
10 conventional block polymer surfactants.
The above specification, examples and data provide a
complete description of the nature, manufacture and use of
the composition of the invention. Since many embodiments
of the invention can be made without departing from the
15 spirit and scope of the invention, the invention resides in
the c:aims hereina~ter appended.
